The present invention relates generally to the field of milling machines, and more particularly to an electric floor milling machine for indoor use.
Milling machines are commonly used to treat ground and floor surfaces, such as concrete, and to remove floor coverings, such as ceramic tiles and epoxy coatings. Because ground and floor surfaces are among the hardest construction materials, the milling machines powerful enough to treat or remove them must normally be very large and heavy. The power sources for such large and heavy machines are typically internal combustion engines, such as gasoline or diesel engines. Such machines work well for outdoor surfaces and surfaces in open areas, but are difficult, if not impossible, to use indoors. Very large machines will not fit inside many buildings, and the ventilation systems in many buildings are not equipped to deal with the exhaust produced by internal combustion engines. In the event that the machine will fit into the building, it can still be difficult to remove much of the floor surface because the machines cannot accomplish a milling function near walls or into corners and other tight spaces.
As a result, several attempts have been made to adapt conventional milling machines for indoor use, and to design new milling machines for indoor use. For example, U.S. Pat. No. 6,328,387 discloses an apparatus for removing floor coverings that is specifically designed to be sufficiently compact and narrow to be able to pass through doorways of residential buildings, comprising a rotary milling device in a housing supported by hydraulically powered elevating legs with wheels that is propelled by a separate energized vehicle. Further, U.S. Pat. No. 5,533,790 (the '790 Patent) discloses a milling machine for use inside buildings without releasing or emitting large amounts of dust into the surrounding environment, comprising a chassis structure supported by ground-engaging wheels, rotatable milling means, a vacuum system and a separate waste hopper. The '790 Patent further discloses the use of a petrol engine fueled by liquid petroleum gas to minimize pollution emissions.
Although some milling machines have been adapted or designed for use indoors, like those described above, those prior art milling machines still have significant limitations. Most significantly, the prior art milling machines do not provide a single, compact machine that effectively reduces both pollution and dust emissions. Additionally, it is still difficult if not impossible, using prior art milling machines, to reach corners and other tight spaces in the building.
Accordingly, a need exists for a single, compact indoor floor milling machine with improved pollution and dust emissions that can be used to remove flooring material in corners and other tight spaces. The present invention relates to improvements over the prior art as described above, and to solutions related to problems raised or not solved thereby.